Touch-sensitive display devices allow users to interact with computers using fingers, passive styli, active styli, and other input objects. The touch-sensitive display device may detect a touch event each time an input object touches or comes into close proximity with a touch sensor of the touch-sensitive display device. The touch sensor typically includes a plurality of touch-sensing electrodes distributed across the touch sensor to enable capacitance measurements at specific two-dimensional locations (e.g., given by X and Y coordinates). A touch event may therefore be interpreted by the touch-sensitive display device as a user input at a particular two-dimensional location relative to the touch-sensitive display device.